This is a nice addition to the Detailed Info in the Resources Window for Media. It was checked into GIT with the "guessed" sar/dar commented out since it seemed redundant. Thank you to Andrew.

Observations:
1) about "some display aspect ratios ... will look unusually big" - I did not see this as unusual AND whenever the display aspect ratio was big, it perfectly matched the results given by ffprobe outside CinGG.
2) "guessed" seemed to always match "codec" (although guessed would take the equivalent number of, for example, 72x72 as also shown by ffprobe and make it 1:1) AND whenever "guessed" was present, "codec" was too.

So, could we eliminate "guessed" since it was the initial setting before "codec" and "container" were added as correct instead of just a guess?

well, this av_guess function was used by me for guessing aspect ratio of loading assets -:)

hopefully it will never glitch so there will be no need to debug THAT

So, yeah ... you can comment out guessed report line ...